With rapid development of an Internet service and a multimedia application, a service volume of a network is rapidly expanding at an exponential rate. Therefore, the network is required to have a high bit rate data transmission capability and a large throughput cross capability. Therefore, a fiber optical communications technology starts to penetrate to a communications network. In addition, because an optical signal of an all optical network (AON) always exists in an optical form during transmission and switching in the network without undergoing optical-to-electrical conversion and electrical-to-optical conversion, fiber optic communications is being comprehensively pulled to the all optical network.
Optical cross-connect (OXC) is an important link in the all optical network. Main functions of an OXC node include switching between dimensions, switching between wavelengths in a dimension, wave adding/dropping on a local wavelength, and the like. A wavelength in the switching between dimensions or in the switching between wavelengths in a dimension is referred to as a pass-through wave. Adding a local wavelength to a dimension is referred to as wave adding, and dropping a wavelength of a dimension to a local node is referred to as wave dropping. Requirements of a network for the OXC node are as follows: a large switching capacity, being transparent to a wavelength and a data format, a low blocking rate, low power consumption, a high integration level, low costs, and the like. A key part of the OXC node, that is an optical switching apparatus such as an optical switch, is mainly used for optical signal switching, that is, outputs an input signal from a corresponding output port according to a routing-configured mapping relationship.
In an existing OXC node based on the optical switching apparatus, an optical switch for wavelength switching is shared by wave dropping performed on a wavelength of another network node and wave adding performed on a wavelength of a local node. A pass-through wave may spare an idle port for wave adding only when wave dropping is performed, and wave adding and wave dropping may be performed on signals of a same wavelength on the optical switch at the same time. Therefore, the same wavelength may bring crosstalk.